


Back Seat Slut

by Spn_kink_sock



Category: Supernatural
Genre: Alpha Castiel/Omega Dean Winchester, Alpha/Beta/Omega Dynamics, Car Sex, Caring John Winchester, Creampies, Dean in a Dress, Dirty Talk, Feminization, Knotting, M/M, Mpreg, Omega Dean, Pregnancy risk kink, Teacher-Student Relationship, Underage Sex, Unplanned Pregnancy, Unprotected Sex
Language: English
Status: Completed
Published: 2019-11-01
Updated: 2019-11-01
Packaged: 2021-01-16 04:50:42
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 4,364
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21265364
Author URL: https://archiveofourown.org/users/Spn_kink_sock/pseuds/Spn_kink_sock
Summary: The one where Dean gets knocked up on prom night.For a prompt on the kink meme that wanted Dean getting fucked in the backseat of a car in a fluffy dress on prom night.https://spnkink-meme.livejournal.com/151560.html?thread=46877192#t46877192





	Back Seat Slut

It just takes a moment of eye contact, a gesture of looking to the left, a subtle nod from Mr. Novak and Dean is ditching Aaron, the sweet but hapless Beta boy who is ostensibly his date. Ditching him like a bad prom date, because, honestly. Well, you know. He didn’t even bring Dean a corsage with a wrist strap, but three stems of dark red roses because they were romantic. Whatever. They had to be left at home in a vase and Dean had to go to the prom without flowers. What Omega didn’t get flowers at prom?

It didn’t matter though, because, in a moment, Dean has excused himself to go to the little Os room and instead of turning right down the hallway to the restrooms, he’d gone left to the supposedly locked exit to the parking lot. Well, it was a firedoor, so locked unless there was an active alarm. That was broken, always was broken, but not known about except for bad boys like himself. 

He’d talked Dad into lending Baby to Aaron to drive to the prom. Just because, as an Omega, Dean wasn’t allowed to drive, didn’t mean he didn’t want to arrive in style. Dean had made Aaron give him the keys, because hey, he wasn’t about to get ditched at prom by some Beta driving the car that should have rightfully been his. Baby was parked around the back in a shady area of the parking lot, far away from other cars, to save the chance some yahoo would ding their door into one of hers. 

Mr. Novak was wearing his usual black suit and tie when he stepped out of the shadows to meet Dean. He took in Dean with a long look of appreciation, eyes dark with lust. Mr. Novak had been Dean’s health teacher last year and ever since then, he been giving Dean hands on sex education lessons. 

“You look lovely tonight, Dean,” he said, placing his hands on Dean’s ass, which happens to be barely feelable through about a hundred layers of tulle and sequins. Still, he pulled Dean close with his strong, Alpha arms and bent down to kiss Dean’s lips.

“Mmm, cherry chapstick,” Cas said. “You taste delicious. I’m sure your other lips will as well.”

Weirdly, John Winchester was okay with Omegas wearing dresses, but he drew the line at Dean wearing makeup. Still, a guy wanted soft, smooth lips for his Alpha, right?

It didn’t take long until they were in Baby’s back seat. Dean was kneeling, dress thrown every which way, jsut to get the crazy skirts out of the way. It was gorgeous, the dress, frosted mint tulle with silvery sequins decorating the bodice and the top layer of tulle, sweetheart neckline on the bodice that somehow magically made his little Omega titties look much, much bigger. It was gorgeous but it was getting the hell in the way at this moment, with the skirt so big and poufy that there’s hardly room for it and them in the same back seat, but before long, Mr. Novak had managed it somehow and he was licking a stripe with his tongue up and down Dean’s boypussy, giving Dean the best head he’d had ever. Dean was moaning, crying out as softly as he could, but it was good, so fucking good. The best.

Well, best ever since last week when Mr. Novak had done the same thing during a stolen minute in his school office with the door shut.

“Do you want me to fuck your hole or pussy, slut?” Mr. Novak asked, pausing. When Dean hesitated a moment, he slapped Dean’s ass, hard and Dean tried to think fast. He liked his pussy being fucked much better than his hole, but there was a risk, every time, of pregnancy, especially if Mr. Novak didn’t pull out. Though that was part of why it felt better, wasn’t it?

“Fuck my pussy,” Dean said. “Come inside me this time.”

It didn’t take long for Mr. Novak to mount Dean, push his amazing cock inside to the hilt. He was good at fucking too, knew how to press and use his cock to rub on the internal Omega clit. He didn’t need to bother touching Dean’s tiny Omega cocklet. Dean shoved his arm into his mouth so that he wasn’t too loud, still, it was a good thing they were pretty much at the farthest part of the parking log, because Dean was just loving this, the Alpha’s bare cock inside his pussy, knowing he was going to get filled up with come very soon, the growing pleasure building and building. 

Cas fucked him harder and said, “Make noise for me like the slut that you are. You love my cock, don’t you? You love knowing I’m going to fill your slut pussy up with my come, maybe fuck a baby into you tonight.”

Dean lost it at that, coming hard, spraying slick everywhere. All over the damn dress especially and then Mr. Novak was coming too and he wasn’t pulling out, not even after his first spray of semen. He was letting himself get tied up, letting his knot get caught in Dean’s pussy.

Afterwards, it was different than normally. They didn’t have to scurry off, because their fucking was taking place during stolen moments of the school day. Mr. Novak held Dean tightly through the tie, lowering them to spoon together in the backseat of the Impala, even as he continued to fill Dean’s pussy with come. It wasn’t as comfortable as it could have been, because even as big as Baby was, it was still a car backseat and there was the dress to think about. 

Mr. Novak tugged down the bodice so he could play with Dean’s small tits while they were tied up together, rolling the nipples between his fingers, seeing if he could bring Dean to another orgasm. 

“Slutty boy, you’re gorgeous dressed up like this,” he said. “I don’t know why you don’t dress prettier all the time. Those jeans and flannels. They just make me want to rip them off you. If you were my Omega, you’d be in pretty dresses all the time.”

He kissed the back of Dean’s neck, tongued the mating spot, but didn’t mark it. He rolled his hips a little, canting them this way and that to rub against Dean’s internal clit, making the pressure build again, driving Dean to another orgasm. But it was over too soon. His knot, like all Alpha knots eventually, softened, and he pulled out. He gave Dean one last kiss, then helped him out of the car, helping Dean tug himself back into the dress, helping Dean fluff the layers of tulle so that they laid right. 

Under the dress, Dean could feel his damp pussy, not exactly leaking, but he could feel the come inside of him. Luckily, his date was a Beta and wouldn’t be able to smell it on him. Mr. Novak was gone, disappeared back into the school no doubt. Dean made his way back to the school gym with its balloon arches, cheesy photo back drops and crepe paper streamers. The D.J. was playing something totally forgettable but that had a thumping bass line for the students that were dancing. 

His date, Aaron, had found a bunch of his friends and had set themselves up at one of the big round tables. One of them had snuck the game of Risk into the prom and they were near the start of a game. They’d probably be at it for a while.

“Hey, I’m really sorry,” Aaron said as Dean approached him. “I didn’t meant to ditch you like that, but I ran into Ash and he let me know that the guys were setting up a game. We’re probably going to be busy for a while. Maybe you could call your Dad to come get the car? I can get my own ride home and I’ll see you on Monday at lunch.”

“What the hell? I’m being ditched for a game of Risk?” Dean asked. Aaron just shrugged and turned back to his friends. Dean turned to stalk away, but stopped to shout, “Consider yourself dumped!”

They weren’t supposed to leave the prom, not until it was over, but Dean, as before, slipped out unnoticed. Home was only half a mile or so, so he didn’t even think about Baby. She’d be safe enough in the back lot until Dad could get her tomorrow. He gathered his skirts around him, thanked his past self for insisting on wearing the silver lame chuck Taylor’s rather than fancy heels with the dress and stalked his ass on home. 

His Dad was watching TV, waiting up for him on the sofa. 

“Boys suck,” Dean said, plunking his sequin and tulle covered ass on the sofa next to Dad, who pulled him close into his side. 

Dad sniffed and said, “Smells like you had a pretty good time. Deanie, you’re being safe, right?”

Dean didn’t answer. 

“Dean, promise me that you’ll make sure that Alpha I smell on you uses condoms from now on. “

“Yeah, ok. I promise.”

It wasn’t a lie. He meant it. For now at least.

“Well, go shower and get out of that ridiculous thing. I thought maybe you might want to go out for a late night burger and fries.”

***

Dean had a feeling. He hadn’t even had morning sickness yet but he had a feeling about things, so he took a pregnancy test. Positive.

He left for school early. Marched right to Mr. Novak’s office first thing. As Mr. Novak looked up, his eyes glittering blue, Dean dropped the pregnancy test on his desk. Mr. Novak examined it carefully, asked, “This is yours?”

Dean nodded.

“Shut the door behind you, Dean,” Mr. Novak said. 

Dean had thought there would be a lot of that whispered kind of shouting that you here when people are arguing but don’t really want to be heard. He had thought that right off the bat, Mr. Novak would deny it could be his baby, that Dean was such a slut that the baby could have come from a dozen other Alphas. Dean thought, maybe, that Mr. Novak would demand he get an abortion or try and talk him into it. He even wondered if there would be pleading for Dean to name some other boy as he father or just about anything other than what happened.

Mr. Novak got out a little velvet box from his pocket. It looked a little worse for the wear, like it had been carried around in that pocket for a while and it had some pocket lint on it. Mr. Novak opened the box and inside was a diamond ring. It was an engagement ring. There were three big, squareish diamonds on a plain band of silvery metal. They sparkled like crazy, even in the dim, fluorescent lighting of the office.

“Dean, I knew the instant I laid my eyes on you, that you were the one. I had wanted to wait until you were eighteen to ask this question, but it seems like we shouldn’t wait any longer. Would you marry me? Be my Omega.”

“We’re getting married?” Dean asked, dumbstruck. Yeah, he’d been in love with Mr. Novak for forever, since they first met, but he wasn’t anything to the man but his dirty little secret. His reason for sneaking around. His slut. 

“If you consent to be my Omega, yes,” Mr. Novak said. Then he walked around from behind his desk and got down on one knee. “I understand it is customary to ask on one knee. Is that the reason you haven’t said yes yet?”

Dean’s eyes filled with tears. This wasn’t what was supposed to happen. This wasn’t the story as he had understood it. Not that he didn’t dream about getting married to the man, but it wasn’t supposed to happen. Mr. Novak didn’t think about him like that. Dean turned on his heels and ran, down the hall, out of the school and all the way home. He ran past home, down the street to Uncle Bobby’s junkyard. Bobby owned a lot more land than was covered by old cars, so he skirted the fence surrounding the junkyard and went down the ravine to the creek. 

There was an old willow tree on the bank of the creek that just perfect for sitting in and thinking. There was a low branch that swept out over the creek and it was easy work to climb up into the fork. They’d built a tree fort there years ago, him and Dad and Bobby and though it was mostly unused and unloved, Bobby kept it up, fixing it when it was broken. Dean hid among the late spring lacy leaves of the tree and he tried to think.

Dean stayed all day, even though his stomach rumbled with hunger, even though he had to pee in the bushes, which was inconvenient. Dean’s cocklet was so small that most of the time, he just sat down to pee. Out here in the woods, he just barely missed pissing on his own shoes. It might have been easier if he was wearing a skirt of some kind, not have to deal with pants and squatting and such.

That was part of the thing. If he let himself be Mr. Novak’s Omega, would the man want him to wear those pretty, fancy dresses and nothing else? Dean loved the fancy dresses, every now and then. He’d felt pretty, fancy, sexy even in his prom dress, but you didn’t wear something like that every day, He liked his jeans, his flannels. He liked being able to head down to the ravine and no worry about if his clothes were going to catch and get torn up on some sticker bush. He might be just barely a boy, but he liked being all the boy he could be. Did he even want to grow up and have this baby?

It wasn’t like it would be a shocking thing. Omegas his age got pregnant and married all the time. Omega bodies were just ready for it sooner. Their biological clocks started ticking sooner and louder than other people’s. His old friend Michael had had a baby last year. No one would think worse of him if he just had it. Dad had been talking about Dean finishing high school and even going on to college, but Dean had never been sure if that was what he wanted anyway.

Sometime, in the late afternoon, his Dad came down to the willow tree and since Dean didn’t try to shoo him away, he climbed on the platform too. It was just barely big enough for the both of them. Dad pulled him close, wrapping an arm around Dean’s side. He’d been carrying a paper bag, which he put in Dean’s lap. Inside was a plastic triangle shaped clamshell, filled with cherry pie. It was just storebought pie, but it made Dean just about burst into tears. 

“I thought you’d be hungry, seeing as you’re eating for two now,” Dad said. 

“How’d you know?”

“That Alpha of yours. He came around at lunch time to ask me for your hand in marriage. I guess he feels he wants to get it all done properly.”

“What’d you tell him?” Dean asked, miserably, staring at his pie. He loved pie. Why did his stomach roil at the thought of it. Why couldn’t he just dig in? As for Mr. Novak asking for him from Dad, he had no idea what Dad would tell him. To pound sand? That he was glad to get a disobedient, slutty Omega off his hands so easily?

“That I wasn’t the person he should be asking, that it was totally up to you. If you want to marry him, you have my blessing, Dean, and if you don’t, then don’t marry him, just because of the baby.”

“When you were with Mom and she got pregnant with me, why didn’t she marry you?”

It was sort of a rude question. They didn’t talk about it much, how Dad had gotten Mary, his mom, pregnant, but she didn’t want the baby. She’d had Dean, but left long before Dean could remember her. She was an uncertain voice on a once a year phone call that Dean knew she made only out of some kind duty she felt and a monthly check for support. She was an unhappy looking blond woman from a photograph. Dad had raised Dean on his own, with some help from Uncle Bobby. Would Mr. Novak be a photograph to Dean’s baby? Probably one cut out from the yearbook at that, because Dean didn’t have another. It wasn’t like they’d dated like Dad and Mary had. 

“That’s a complicated story and for another time, but you know, I’m kind of glad we didn’t get married now. I mean, I hated it at the time, but it wouldn’t have been a good marriage, I don’t think, because the only reason we would have had was a baby. But this Alpha and you, only you can know if you have another reason to marry him.”

“You don’t care that he’s my teacher?”

John shook his head, obviously not happy about it, but he said, “It’s not the first time it’s happened that an Omega gets knocked up by one of their teachers. It’s kind of expected almost. I don’t object to him in particular. He says he has means beyond his teaching salary. There’s family money, I guess. You’d be well take care of, but that’s not a good enough reason to marry him either. If you don’t, I’ll make sure you’re taken care of, you and your baby. You ready to come home now?”

“Yeah,” Dean said, feeling better. At least Dad didn’t hate him for it. 

On the walk past Bobby’s fence, Dean said, “I love him. I just don’t think he loves me. Not like that way. To him, I’m just a...”

Dad didn’t let him finish, “You think he doesn’t respect you because you put out for him in the back seat of the Impala.”

“You knew?”

Dad chuckled a little. “Ugh. I couldn't miss the scent of it, all over the car. Took a whole can of scent block to get it in driveable condition. Don’t look so shocked. That was far from the first time the back of the Impala has seen some action. I’m pretty sure you were conceived on that back seat.”

“Oh, gross,” Dean said. He did not want to think about his Dad having sex with anyone, much less at the same place where he’d just had blisteringly hot sex less than a month ago.

“Burgers tonight?”

“Nah, I think the baby wants tacos. And this piece of pie.”

When they returned from dinner that night, Mr. Novak was waiting for them on the porch. 

“Hello, Dean,” he said.

His dad looked at Dean, as if wanting to know if Dean wanted him to send Mr. Novak packing. 

“I guess we gotta talk sometime, Mr. Novak,” Dean said. “Seeing as I’m having your baby.”

“Seeing as you are, perhaps you could call me by my first name,” he said. “Castiel.”

“Cas,” Dean said. “I like it. Dad, me and Cas are just gonna talk here on the porch. Is that okay?”

“I’ll be inside,” Dean’s Dad said. 

There were a couple of chairs on the small porch, but Cas took a seat on the steps, so Dean took one a few steps away.

“I spoke the truth this morning when I said that I knew you were the one the instant I laid my eyes on you, however, I believe I misapprehended the amount you returned my feelings. Regardless, i find myself pleased at the thought that I will be a father. I look forward to parenting with you in whatever amount you think best for our child. You also need not worry financially. I am willing and able to provide a generous child support payment.”

“Cas, I don’t want you to be just a child support check,” Dean said. His mom was that. It sucked. “But how can you want to marry me? I’m just the side chick. I’m just some slut you fucked in the backseat of a car.”

“Is that what you think I think of you?” Cas asked. 

Dean nodded.

“Well, yes, but you are far more than that. You’re the center of my world, Dean. Every day i don’t see you is dull and gray. You are not a side chick. You are my front and center chick. If it were my choice, you would be my first sight in morning and last at night. And yes, it was delightful to fuck in the back of that car, but only because I want to fuck you in every possible location. Again and again and only you for the rest of my life.”

“You’re serious. You wanna marry me?”

“I love you Dean. It was love at first sight and it killed me that we had to keep things a secret.”

“Lemme see that ring again,” Dean asked. Castiel dug it out of his pocket, same old lint dusted velvet box. “You carry it everywhere with you?”

“I have since I bought it two weeks after meeting you. I knew I would ask you the moment the time seemed right. The time isn’t exactly right, is it? We seem to have done things all out of order, haven’t we? But I don’t think any time else will be better.”

Dean didn’t think there was a better time either. He didn’t want Cas to be some yearbook cut out picture to his baby. He wanted Cas there to change diapers with him. He kind of thought he wanted Cas to give him a sibling of some kind for this baby, because Dean had always wanted a brother, thought he’d really missed out, not having one. 

“What did my Dad really tell you when you asked for my hand in marriage?”

“That you were the person to ask, but that if I ‘screwed this up and break your heart,’ he would break every bone in my body. I have this creeping fear he could do it, too. Also, that if abandoned his grandchild, he would find me and make me pay.”

“Yes,” Dean said. He opened up the box and took out the ring. He put it on his own finger and held it up to the porch light. It sparked even in the dim yellow light. It was, maybe a little too big, but he’d heard your fingers sometimes swelled a bit when you were pregnant, so maybe that wasn’t such a bad thing. “Let’s get married. Maybe it’s a dumb idea, but I think I want to marry you.”

***

The wedding was towards the end of the summer, not too big because Dean’s side did’t have a lot of people and while Cas had a big family on his side, apparently most of them couldn’t be trusted not to be a big bag of dicks, so only Cas’s brother Gabe came. It didn’t matter that it wasn’t a big fancy wedding. He still got his fancy dress. 

It was lace but also had a million layers of tulle and some sparkly things sewn to the bodice. Miracle of miracles, it did not make him look pregnant, even though Dean’s baby bump had made an early appearance, so big and sudden that he’d been convinced it was twins until the OM gyn doc had used the ultrasound to determine that it was just one, very healthy baby, about the size of a lime.

After the ceremony and eating the wedding pie Dean had insisted on, Dad gave him a little wrapped box. Dean opened it up and inside were the set of keys to the Impala. 

“Legally, I had to title her to Cas,” Dad said. “But I made sure Cas understands that she’s your car. Take good care of her.”

Dean threw his arms around Dad’s neck, and just because of the baby making hormones that were driving him crazy anyways, he cried. Though it couldn’t have been all hormones because either it was really dusty or Dad was crying a little too.

Later, they drove away to their honeymoon, just a cabin near a lake, Cas at the wheel of the Impala, Dean leaning against his side. Not far outside of town, Cas said, “There’s this place we used to go when I was a teenager, near the old quarry. Nice and out of the way. A good place to park for a while.”

They pulled into a dark and shady lane that overlooked a lake that had filled up in an old mining quarry. The trees were dense and no one was around, seemingly for miles. You’d think there’d be kids swimming in a lake that pretty, so bright and turquoise blue, but then Dean caught sight of the signs warning about how toxic the lake was.

“It’s very pretty and perfectly safe, so long as you don’t go in the water,” Cas pronounced. 

They ended up in the back seat again, Dean on his knees, chest to the seat, poufy skirts all over everywhere as Cas ate out his pussy with slow, tormenting strokes of the tongue. Cas was taking his time, enjoying every crevice of Dean’s pussy, every shiver and every moan he could elicit from Dean. When Dean keened in frustration, Cas petted the base of his spine and just dove deeper with his tongue, then gripped Dean’s hips, steadying him and holding him in place. 

Only after Dean had collapsed to the seat as a pile of quivering goo did Castiel press his body into Dean’s, rubbing Dean’s baby bump as he worked in and out, building slowly but steadily to a fervor. “So happy you’re having my baby,” Cas said. “So happy that you’ve become my sweet little slut.”

END


End file.
